Illumination system

Abstract

The addition of DMD illumination modulator(s) 702 in series with projection SLM(s) 706/709 to produce high-performance projection displays with improved optical efficiency, reliability, and lower maintenance requirements. This approach eliminates the vibration, audible noise, and safety problems associated with high speed rotating color filter wheels 203 commonly used in SLM projectors and controls the light applied to individual areas of the projection SLM(s).

1. An illumination system comprising:
 a white light source generating a light beam path along a light path;  
 an illumination modulator on said light path, elements of said illumination modulator switched between a first and a second state;  
 said illumination modulator elements in said first state directing light to the surface of a yellow dichroic mirror;  
 said yellow dichroic mirror directing red and green light to a color splitter;  
 said color splitter directing said red light from said yellow dichroic mirror to a dedicated red spatial light modulator;  
 said color splitter directing said green light from said yellow dichroic mirror to a dedicated blue-green spatial light modulator;  
 said illumination modulator elements in said second state directing light to the surface of a magenta dichroic mirror;  
 said magenta dichroic mirror directing red plus blue light to said color splitter;  
 said color splitter directing said red light from said magenta dichroic mirror to said dedicated red spatial modulator; and  
 said color splitter directing said blue light from said magenta dichroic mirror to said dedicated blue-green spatial light modulator.  
 
   
   
     2. The illumination system of  claim 1 , green and blue light sequentially present at the surface of said blue-green spatial light modulator, wherein the duty cycle between said blue and green light is controlled by switching the binary state of said illumination modulator. 
   
   
     3. The illumination system of  claim 1 , wherein said illumination modulator modulates the color light by turning OFF selected elements of said illumination modulator to control the amount of illumination to said spatial light modulators. 
   
   
     4. The illumination system of  claim 1 , said illumination modulator having fewer elements than said spatial light modulators. 
   
   
     5. The illumination system of  claim 1 , said illumination modulator having more pixel defects than said spatial light modulators. 
   
   
     6. The illumination system of  claim 1  said TIR prism directing said blue and green modulated light and said red modulated light to a display projection lens. 
   
   
     7. An illumination system comprising:
 a white light source providing a light beam;  
 a color splitter directing red light to a dedicated red spatial light modulator;  
 said color splitter directing cyan light along a light path to an illumination modulator;  
 elements of said illumination modulator switched between a first and a second state;  
 said elements in said first position directing light to a blue dichroic mirror;  
 said blue dichroic mirror directing blue light to a dedicated blue-green spatial light modulator;  
 said elements in said second position directing light to a green dichroic mirror; and  
 said green dichroic mirror directing green light to said dedicated blue-green spatial light modulator.  
 
   
   
     8. The illumination system of  claim 7 , said green and blue light sequentially present at the surface of said blue-green spatial light modulator, wherein the duty cycle between said blue and green light is controlled by switching the binary state of said illumination modulator. 
   
   
     9. The illumination system of  claim 7 , wherein said illumination modulator modulates the color light turning OFF selected elements of said illumination modulator to control the amount of illumination to said spatial light modulators. 
   
   
     10. The illumination system of  claim 7 , said illumination modulator having fewer mirrors than said spatial light modulators. 
   
   
     11. The illumination system of  claim 7 , said illumination modulator having more pixel defects than said spatial light modulators. 
   
   
     12. The illumination system of  claim 7  comprising:
 a first projection lens directing said modulated red light onto a viewing screen; and  
 a second projection lens directing said modulated blue and green light onto said viewing screen.  
 
   
   
     13. The illumination system of  claim 12 , wherein said modulated red and blue-green light is electronically converged. 
   
   
     14. An illumination system comprising:
 a light source producing a beam of light comprising three primary color components along a light path;  
 a first spatial light modulator operable in a first and second state and receiving at least a first and second primary component of said light beam;  
 a first color filter directing said first primary color component to a second spatial light modulator when said first spatial light modulator is in said first state;  
 a second color filter directing said second primary color component to a second spatial light modulator when said first spatial light modulator is in said second state;  
 a color splitter separating a third said primary color component from said beam of light and directing said third primary color component to a third spatial light modulator.  
 
   
   
     15. The illumination system of  claim 14 , wherein said third primary color component is the red primary color component. 
   
   
     16. The illumination system of  claim 14 , wherein said color splitter is a prism. 
   
   
     17. The illumination system of  claim 14 , wherein said first color filter is a dichroic filter. 
   
   
     18. The illumination system of  claim 14 , wherein said first color filter is a yellow filter. 
   
   
     19. The illumination system of  claim 14 , wherein said second color filter is a dichroic filter. 
   
   
     20. The illumination system of  claim 14 , wherein said second color filter is a magenta filter. 
   
   
     21. The illumination system of  claim 14 , wherein said color splitter separates said third primary before said beam of light is received by said first spatial light modulator. 
   
   
     22. The illumination system of  claim 14 , wherein said first spatial light modulator receives said beam of light including said third primary before. 
   
   
     23. The illumination system of  claim 14 , wherein said color splitters separates said third primary after said first spatial light modulator directs said beam of light said color splitter separates said third primary.